Sort by extension by entering the whole extension (including the dot) in the file/path box.
Sort on date modified by clicking on the column header.
Where do we find this 'file/path box'? We can sort by the path column, but that's not by file type. I'm working with v 1.36.479 and see a list of drive letters next to the 'scan' button, but don't see any place in 'options' or the main screen to enter an extension.